How to use utf8.nfcnormalize and utf8.nfdnormalize?

[rogeriodec_games]

I’m trying to understand the effective use for utf8.nfcnormalize and utf8.nfdnormalize.
But I see no difference here:

local a = 'ação'
print(utf8.nfcnormalize(a)) -- ação
print(utf8.nfdnormalize(a)) -- ação

Any ideas?